Question

I tried ‘x = y ** e’, but that didn’t work.

Answer 1

use the pow function (it takes floats/doubles though).

man pow:

   #include <math.h>     double pow(double x, double y);    float powf(float x, float y);    long double powl(long double x, long double y); 

EDIT: For the special case of positive integer powers of 2, you can use bit shifting: (1 << x) will equal 2 to the power x. There are some potential gotchas with this, but generally, it would be correct.